Process for cracking hydrocarbons



Feb. 2, 1932. G. EGLOFF 1,343,664

PROCESS FOR ,CRACK ING HYDROQARBONS Filed Dec. 4, 1919 Rerun stills Transpor'ii line forRDBoi ms,

z Mix-i,

chum er ess in which-the hot Patented Feb. 2,1932.

" UNITED STAT S PATENT OFFICE A CORPORATION OF SOUTH DAKOTA rnocliss roncnacxme mnnocmons Application and December 4, 1919. Serial no. 342404.

- M invention relates to a process for treat ing ydrocarbons and larlyto 'a process for maimng in pressure utilizing the heat re'-.

bined, with the raw ()1 process in which the-pressure distillate bot-vtoms, from the neighboring re-run stills, are

collected in a transporting line while they are in a heated condition,.as when they come direct from the distilling zone and are pumped backinto the raw oil charge about -to enter the cracking zone of a still,thereby transferring a portion of their heat to the raw 'oil and beingagain subjected 'with the raw oil to treatment in the crackin tubes; toprov vide a process in which, besi es the feature of utilizing to agreater extent theheat generated, the hot pressure distillate bottomsare more completely cracked by being retreated in the same or a relatedstill as they are com- I bined with the raw .oil charge of said still;to provide a novel type of apparatus for car-- rying out this processand in general to'provide a process and apparatus of the characterreferredto.-

' In thedrawing I have shown a side elevation of a still, partly insection and with parts broken away, showing the double pump arrangementcombining the pressure distillate bottoms from neighboring rerun the rawoil.

' Referring more particularly to the drawiug, within the still 1,consisting of "a furnace portion 2 heated by" suitable burner 3, aremounted cracking tubes 4 situated above the furnace and receiving theraw oil chargethrough charging pipe- 5 and mixing chambar 6. Thecharging pipe is controlled by .valve 7 and is provided with a suitablepump refers more particudistillate bottoms to wraisethe temperature ofthe fresh incom ng stilland there com'- charge; to provide a chargingpipe 26a. Theoil vaplors after being cracked in the tubes 4 .rise trough pipe 5.1nto a vertical tube considered as a whole 8, which con-.sists in a dephlegmator or separator ortion 9 an a lower expansion orvapor c amber 10. The oil vapors rislng 1nto the expansion chamber aredistributed therein by a baflle cone 11. .The heavier residue is drawnoff from the bottom of the vapor chamber through a pipe 12 controlled byvalve 13.

ous'r'av senor-r, or mnnrnnnnucn msasi sis stones. :ro umvnnsn. ornrnon-I UCTS COIPA'NY, OF CHICAGO, ILLINOIS,

The l1ghter vapors rising in the separator portlonv are directed throughthe gooseneck 14 to the pipe coil 15 in the water condenser 16. Thiscondenser is mounted upon any suitable standard 17. The distillate fromthe condenser passes to the receiver 18 through pipe 19. A drawolf 20controlled by valve 21 provides a means of taking oif the distillatefrom time to time. A suitable gauge 22 of a common type is mounted onthe side of the receiver and denotes the quantity of distillate in thereceiver. Apressure gauge 23 registers the pressure upon the system.

A pressure valve 24, together with the drawofi valve 21 and the valve 13in the residuum line provide a means of regulating the pressure in thesystem. My inventionconsists in introducing pressure distillates'orpressure distillate bottoms from any source, preferably neighboringstills, while the'bottonis' are'yet' in a heated condition and beforethey are allowed to cool or before they have been passed through waterof aerial coolers, through a charging pipe 25 a suitable charging pump26 and a pipe lirie 27, which-charges the pressure distillate bottomsdirectly tothe charging line of'the still through the mixing chamber 6.The

valve. Th introduction of these pressure distillate bottoms while in aheated condi-.

27 may lie-regulated by the valve 28 and the amount of distillateintroduced into 'the'system controlled by this tion,-besidestheadvantage of retreating said? distillate bottoms, tends to transferthe heat thereof to the raw oil charge.

It will be seen that this will greatlyecono- 1 mize the heat of thestill, into which the pressure distillate bottoms are charged. A refluxline 29 is tapped into the lower portion 2 I eeaeee of the separatingchamber of the dephlegmator to direct the reflux condensate from thedephlegmatoi' back to the charging line 5 through the mixin chamber 6.This reflux 5 line 29 is controlled y a valve 30.

' The following illustrative run may be given: Taking gas oil from themid-continent field, such as Kansas or Oklahoma yield, say of 32 Baum;this gas oil is charged into m the cracking zone and is heated to atemperature of from 750 to 900 F. A suitable pressure say, from 50 to150 lbs. is maintained on the system during the entire operation. Gasoil treated in this manner yields 5 from 30% to 40% of gasoline or otherlow boiling point hydrocarbons havinganend point of 400 F. e Whereas,before utilizing the hot pressure distillate bottoms,.by charging samemixed at with thechargingoil into the cracking still, I therewasconsumed' per gallon of gasoline made approximately 95,000 E. t. u.;after adding the hot pressure distillate bottoms the 'B. t. 11 value pergallonof gasoline dropped 25 to 87,000. In carrying out the foregoingrun, I utilize from to hot pressure distillate bottoms, mixed with thegas oil, although fa higher percentage of the distillate bottoms may beused. These hot) distillate bottoms impart heat to'the gas oil and serveto materially lower the quantity of fuel, as well as the time requiredto crack the oil. By the term distillate bottoms, it is meant that Iutilize that portion of distillate resulting from the cracking of oilwhich has accumulated in the bottom of a re-run still, and which has aboiling point above 450 F. In other words, by practicing my process afuel saving of from five to ten percent in 40 cost per gallon ofgasoline may be efiected.

ll claim as my invention: A process for converting relatively heavy intorelatively lighter hydrocarbon oilscomprising initially subjecting theoil to crack-' mg conditions of temperature and pressure while flowingthrou h a heating coil disposed within a furnace, elivering the heatedoil from said coil to an enlarged reaction zone from which nounvaporized oil is permitted 5a to return to said'heating coil,subjecting vapors issuing from said enlarged reaction zone to refluxcondensation, simultaneously introducing to a mixing chamber hot refluxcondensate separated from the vapors under- .55 going refluxcondensation, hot pressure distillate bottoms and a quantity of freshcharging oil for the process, and supplying the commingled oils directlyfrom said mixing chamberto said conversion unit.

at eus'rav Esters.

